The present invention relates to air springs. In particular, the invention is directed to a hydro-damped air spring.
Air springs have been used for motor vehicles and various machines and other equipment for a number of years. The springs are designed to support a suspension load such as a vehicle. The springs are often combined with a separate shock absorber device in the suspension that functions to dampen oscillations. The air spring usually consists of a flexible elastomeric reinforced sleeve that extends between a pair of end members. The sleeve is attached to end members to form a pressurized chamber therein. The end members mount the air spring on spaced components or parts of the vehicle or equipment on which the air spring is to be mounted.
The internal pressurized gas, usually air, absorbs most of the motion impressed upon or experienced by one of the spaced end members by which the air spring is mounted. The end members move inwards and towards each other and also away and outwards from each other as the motion of the suspension requires.
The air spring of the present invention combines both traditional air spring characteristics and components with internal hydro damping. The air spring has an upper retainer, a piston, an elastomeric sleeve secured to the upper retainer at a first end and secured to the piston at the lower end, and a damping device. The damping device has an upper and a lower variable volume chamber and a channel connecting the two variable volume chambers, and a damping fluid contained within the damping device.
In an aspect of the invention, one of the variable volume chambers may have a bellows configuration. The sleeve forming the bellows may be made from a reinforced elastomeric sleeve or may be a molded sleeve. The corrugations in the bellows may be formed from a series of external rings, molded in rings, or elongated rings.
In another aspect of the invention, the lower variable volume chamber is located within the piston and the upper variable volume chamber is located within a chamber formed by the secured elastomeric sleeve.
In other aspects of the invention, the channel connecting the two variable volume chambers is a continuous circular channel. To assist the channel in the flow of the damping fluid, and reduce excessive forces in the suspension, the damping device may have a quick relief valve.